Purpose: :
Diseases of the anterior segment, such as Fuchs’ EndothelialCorneal Dystrophy (FECD), influence central corneal thickness(CCT), as do factors such as intraocular pressure and genetics.Increased CCT is a known late stage FECD finding; however, theassociation between earlier stages of FECD and CCT is less clear.We examined the relationship of FECD severity and CCT in subjectsfrom the FECD Genetics Multi-Center Study.

Methods: :
Subjects were recruited as part of a study to identify geneticfactors underlying FECD and consist of index cases, family membersand additional non-familial cases and controls. Subjects underwentslit lamp biomicroscopy for FECD and received a grade for eacheye from 0 (no guttae) to 6 (>5mm confluent guttae with cornealedema). A total of 1662 eyes from 997 subjects were examinedfor associations between FECD grade and CCT measured by ultrasonicpachymetry. A multivariable model was fit to determine the effectof FECD grade on CCT, adjusting for eye, age, race, gender andfamilial relationship to index case. Generalized estimatingequations methodology was used to account for the correlationbetween eyes within a subject. All comparisons are evaluatedbased on the relevant contrast from the model.

Results: :
CCT increased with increasing FECD grade in both index cases(grades 3 or greater, p<0.01) and affected family members(grades 4 or greater, p<0.01) compared to subjects with agrade of 0. Additionally, affected family members of the samegrade had, on average, thinner corneas than the index patientsfor FECD grades of 3, 4 or 5 (p<0.03). Age, race and genderwere not found to be significantly associated with CCT.

Conclusions: :
CCT increases with severity of FECD, including at grades forwhich corneal edema was not a notable grading criterion. Forseveral higher grading levels, affected family members demonstratedthinner corneas than corresponding index cases. Further analysisto determine the effect of intraocular pressure on these resultsis in progress.